US President Bill Clinton left Japan Sunday to rejoin Middle East peace talks in Camp David after reporting progress between Israeli and Palestinian negotiators, reported AFP.

Clinton, who departed aboard the Air Force One Boeing 747 from the US air force Kadena base in Japan's Okinawa Island, refused to speculate on the chances of success.

He left Japan immediately after a three-day Group of Eight summit, cutting short his scheduled visit by several hours, said the agency.

"I cannot comment yet on the respective positions of the parties because they're going on and it would violate my understanding," Clinton told reporters shortly before departure, referring to a news blackout.

Clinton had arrived in Japan a day late on Friday to keep the negotiators at the table.

US Secretary of State Madeleine Albright stepped in to mediate in his absence.

Since then, "there has been a lot more sort of systematic effort with the groups on a lot of issues," Clinton said before starting a breakfast meeting with British Prime Minister Tony Blair, AFP added.

Meanwhile, a senior Israeli source told Reuters that despite Clinton's optimism, the mood in the Israeli delegation was somber.

"Israeli Prime Minister Ehud Barak is in a very gloomy mood," the source said late Saturday.

The source said chances for a deal seemed to be diminishing and predicted that Clinton would have just 24 hours from the time he returns to take stock and try to turn things around.

Monday night would be critical, the source said. "If Clinton succeeds, the Israeli delegation will stay until Friday and we'll have an agreement. And if not, then we'll go home."

Israeli officials said earlier that Barak's chief of staff planned to leave on Sunday. About 20 of the 50 experts in Barak's delegation had already gone home "because of a lack of progress in the negotiations and a lack of work to do," Israeli officials said late Saturday, Reuters said.

The group of senior Israeli officials and technical experts were standing by at a facility near Camp David to work out the nuts and bolts of a final Middle East peace agreement, said Reuters - (Several Sources)